<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="../js/demo01.js"></script>
    <style>
        #adv{
            display: flex;
            width: 220px;
            height: 220px;
            justify-content: center;
            align-items: center;
            justify-content: space-between;
        }
    </style>
</head>
<body>
    <div id="adv">
        <button id="left" onclick="leftPic()">&lt;</button>
        <button id="right" onclick= "rightPic()"">&gt;</button>
    </div>
    <!-- <button id="left" onclick="leftPic()">&lt;</button>
    <img id="img">
    <button id="right" onclick= "rightPic()"">&gt;</button> -->
    <img src="https://img2.baidu.com/it/u=742684958,470346722&fm=253&fmt=auto&app=138&f=JPEG?w=800&h=1000">
</body>
</html>